There have been many inventions and patents for self-cooling beverage containers. The direction taken by inventors in the past can be in any one of these approaches:
(A) Inventions proposing endothermic or exothermic chemical reactions to produce a chilling or cooling effect in the beverage.
(B) Inventions proposing use of refrigeration effect by compression and expansion of a liquefied gas causing heat to be absorbed, producing a refrigerating effect in the beverage.
(C) Inventions proposing use of desiccant absorbing agents and water to produce a cooling effect on the beverage.
(D) Inventions proposing use of portable power source to cool the beverage.
(E) Inventions proposing use of natural evaporative/cooling process (without power/chemical means) to cool the beverage.
The first group of devices generally requires two or more chemicals to be combined quickly to produce an endothermic or exothermic reaction. An example of an endothermic type chiller is the ICE PACK. The ice pack is a product that uses ammonium nitrate and water to absorb heat rapidly for emergency cooling in medical applications. Several devices depend on similar endothermic reactions to produce a chilling effect that can be put to effective use for commercialization.
The second group of devices generally relate to chilling devices. The household refrigerator belongs to this group of devices. The refrigeration effect occurs when a compressed and liquefied gas is expanded through a small aperture. The evaporation of the liquefied gas to a gaseous state causes considerable heat to be absorbed through the walls of the expansion tube, thereby producing a refrigeration effect.
The third group of devices use desiccant absorbing agents and water. Typically, a water gel is smeared on the inside walls of a first sealed and evacuated chamber. A second sealed chamber contains a desiccant that absorbs the water vapour. By opening a small passage way between the first chamber and the second chamber, rapid vaporization of the water in the first chamber occurs, resulting in cooling. The absorbing desiccant usually heats up to a high temperature due to the heat of condensation of water vapour removed from the first chamber. Both a heating and cooling effect may be obtained by this method.
The fourth group of devices relies on well-known electrical effects for both heating and cooling.
Devices of the first group (chemical endothermic and exothermic reactions) generally rely on toxic and environmentally unfriendly chemicals. They have not been successfully used in the commercial applications for either the food or the beverage industries. Existing devices of the second group require very bulky pneumatic circuits, and cannot economically be used in small containers such as beverage cans or food cans. Devices of the third group have been applied in some food and beverage applications but only under expensive research programs. Even so such devices still do not appear to hold any promise of commercialization due to the expensive designs involved and the toxic nature of the chemical desiccants involved.
Containers for beverages are known in which the components of this chemical reaction are arranged separately in respective compartments of a chamber formed between a first receptacle, containing the beverage, and a second outer receptacle into which the first receptacle is inserted. The components mentioned above generally consist of a liquid and a salt, present in granular form, and the reaction between them is initiated by tearing a diaphragm separating the two compartments, for example by means of a breaking device integral with an inward-flexible base of a second receptacle.
There are some self-cooling devices using Peltier effect to cool beverages. Such uses for devices using the Peltier effect include small applications as small as a beverage cooler which is powered by a laptop using the USB wire. However such devices are not effective in cooling beverages due to their extremely low efficiency in using electrical energy to create a thermodynamic effect.
The approaches taken seem to be a self-cooling or self-chilling beverage container. Even though there are many inventions for such a product, these suffer from a number of disadvantages:                high unit production cost leading to a high retail price for a one-time use        ecological damage caused by the self-cooling unit in the beverage container        problems in re-cycling the beverage container due to existence of self-cooling unit        use of chemicals to produce a cooling reaction causing possible        contamination of the beverage        
U.S. Pat. No. 6,266,974 B1 (W. C. Linden Inc.) proposed a refrigerated beverage mug which includes a self-contained mechanical refrigeration unit which is powered by a power unit mounted onboard the beverage mug. The mechanical refrigeration unit is a closed loop system which is mounted to the beverage mug and includes a compressor, a condenser, an expansion flow passage and an evaporator. The condenser and the evaporator are integrally formed with the main body of the beverage mug while the compressor is mounted to the beverage mug for circulation of a refrigerant through the condenser, the expansion flow passage and the evaporator. The power unit includes a chamber which contains a pressurized, expansible fluid such as liquid nitrogen, which is selectively released for passing through a pressure chamber of the compressor to power the compressor and the mechanical refrigeration unit. A manifold is integrally formed into the compressor housing for passing the expansible fluid from the compressor and across a portion of the condenser.
U.S. Pat. No. 7,178,343 B2 (Innovative Displayworks Inc.) discloses a wine cooler. It uses a thermoelectric cooling system includes a thermoelectric cooling system comprising at least one thermoelectric couple, each thermoelectric couple having a cold and hot junction. This invention uses a thermoelectric chip and a heat sink. The means of supplying power to the at least one thermoelectric couple is a 12 V DC source.
The inventor has observed that while there is great interest in such an invention, there does not seem to be any viable product meeting the requirements for a self-cooling or self-chilling beverage container. The inventor has taken a different approach to propose a self-cooling or self-chilling device for beverage containers. Such an invention would not only meet the requirement for a beverage to be self-cooling or self-chilling, but also meet these criteria as well:                practical,        cost effective,        simplistic design,        easy to use,        safe for use, and        does not contaminate the beverage contents or the environment        
What is needed, therefore, is a new approach for a self-cooling unit for a beverage container that is portable, and provides a self-contained miniaturised cooling means using electrical power without the need to freeze or chill the container or beverage first. It is also desirable to have such a container efficiently cool a beverage within the beverage container without the need to cool the surroundings of the beverage container in the process. It is further desirable that such a self-cooling unit be re-usable to offset the costs of such a self-cooling unit.
What is more desirable is if the self-cooling or self-chilling electrical-powered unit can be portable and re-usable so that with sufficient electrical power sources, it has the capability to cool more than 1 beverage payload.
One consideration is to create an empty mug or container or receptacle with such an electric powered self-cooling or self-chilling device. Beverages can then be used to fill up the empty container or receptacle or mug.
Creating and manufacturing empty containers or mugs with an electric-powered self-cooling device while costly, would, through re-use, be considered less costly than a “one-time usage” beverage container or beverage receptacle.